Intravenous drug users (IVDUs) are the second largest group in the U.S. to be infected with the AIDS virus. Since methadone treatment is a most effective way to curb needle use, hence needle sharing (which spreads the virus), many see maintenance as an important element in arresting the spread of AIDS among this population. In order to effectively halt the spread of AIDS by IVDUs, addicts need to be recruited and retained in methadone programs. This study explores the ways in which IVDUs are, and can be, attracted to and retained in program, with the ultimate goal of cessation of AIDS-related risky behaviors. The research questions for the proposed project include: 1) HOw are IVDUs attracted to methadone maintenance? 2) Once enrolled in programs, what factors help to retain them? 3) What types of interventions have an impact on AIDS transmission behaviors, i.e., needle sharing and unsafe sexual practices? 4) What role does clinic style and type play in reducing AIDS transmission behaviors among methadone clients? 5) What is the effect of no formal educational intervention on AIDS transmission behaviors? The above research questions will be answered with the use of an integrated methodology. Two hundred and forty respondents will be interviewed. Interviewees will be selected from racial, ethnic and age groups which reflect the composition of San Francisco Bay Area methadone clients, as well as from different types of programs. The in-depth instrument to be used is the life history interview, which is designed to trace an addict's "career"--prior to, including, and subsequent to IV heroin use. Each respondent will be interviewed initially, and then every six months for a period of two years. In this way, the process by which an IVDU gets on methadone, ceases (or does not cease) drug/needle use, adjusts to methadone and changes risky behavior, or fails to remain in treatment and perhaps returns to drug/needle use, can be explored. Analysis of the in-depth interview data will occur simultaneously with its collection, using the "grounded theory" method. The closed-ended questions will be analyzed through a path model of study. This will assist us in discovering which variables are linked and crucial to emerging theory, and with each successive wave of follow-ups our study design will be continually tightened.